Circuit breaker assembly with improved tripping mechanism

ABSTRACT

A circuit breaker assembly characterized by at least three circuit breakers in side-by-side relationship and having improved interconnecting trip means for automatically tripping one breaker when the other breaker is tripped in response to overload currrent conditions, said one and other breakers being disposed on opposite sides of one or more intermediate circuit breakers, and the trip means including an elongated tie bar extending from a trip lever in one outer circuit breaker, through the intermediate circuit breakers, and to the trip lever in the other outer circuit breaker.

Umted States Patent 1191 11 1 3,840,833

Mrenna et al. Oct. 8, 1974 CIRCUIT BREAKER ASSEMBLY WITH 3,069,5l7 12/1962 0516 200/50 c x IMPROVED TRIPPING MECHANISM 311931646 7/1965 3,288,964 11/1966 [75] Inventors: Stephen A. Mrenna; Glenn R. 3 4 045 3 19 9 Thomas, both of Beaver, Pa 3,760,308 9/1973 Misencik et al. 337/43 X [73] Assignee. gassgllllgggusreafiectrlc Corporation, Primary Examiner A T. Grimley Attorney, Agent, or Firm-L. P. Johns [22] Filed: Aug. 21, 1 973 [21] Appl. No.: 390,281 [57] ABSTRACT A circuit breaker assembly characterized by at least 52 us. or 337/43, 200/50 c, 335/35, three Circuit breakers yrelationship and r 1 337/46 having improved interconnecting trip means for auto- 511 1111. c1. Hlh 71/16 metieally pp one breaker when the other breaker 53 Y Field f Search 337 44 45 4 47 is tripped in response to overload currrent conditions,-

337/48 49 50339 34 3 9, said one and other breakers being disposed on oppo- 20050 C site sides of one or more intermediate circuit breakers, and the trip means including an elongated tie bar ex- 5 References Cited tending from a trip lever in one outer circuit breaker, UNITED STATES PATENTS through the intermediate circuit breakers, and to the 1 trip lever in the other outer circuit breaker.

1,473,386 11/1923 Scott; 335/9 X 3/1955 06111161861 200/50 C x 1 Claim, 5 Drawing Figures CIRCUIT BREAKER ASSEMBLY WITH IMPROVED TRIPPING MECHANISM BACKGROUND OF THE INVENTION 1. Field of the Invention:

This invention relatesto circuit breakers and, more particularly, it pertains to a plurality of circuit breakers disposed in side-by-side relationship in which the outer circuit breakers have trip levers that are interconnected for simultaneous tripping independently of the intermediate circuit breakers.

2. Description of the Prior Art:

Generally, a plurality of single pole circuit breakers have been assembled together in side-by-side relationship to provide multi-pole systems. In those systems the automatic tripping of any one of the circuit breakers has resulted in tripping of the other circuit breakers. One disadvantage of tying all of the circuit breakers together for common automatic tripping is that it has not been possible heretofore to automatically trip less than all of the .circuit breakers. Indeed, there are circumstances where it is desirable to automatically trip two tionship.

SUMMARY OF THE INVENTION In accordance withthis invention it has been found that the foregoing disadvantage may be overcome by providing an assembly of circuit breakers which employ direct common trip means between two spaced circuit breakers in the assembly without affecting the intermediate breakers. For that purpose each circuit breaker comprises an insulating housing having oppo site side walls, adjacent side walls of contiguous break ers having aligned openings, each breaker having a trip lever which is rotatably mounted in the openings, the trip levers of the intermediate circuit breakers being interlocked and having aligned openings. The trip levers of the outer circuit breakers being secured together for simultaneous operation by a tie bar extending between the levers and through the openings in the trip levers of the intermediate circuit breakers, whereby the trip levers of the outer circuit breakers operate simultaneously and independently of the trip levers of the intermediate circuit breakers.

The advantage of the trip mechanism for the circuit breaker assembly of this invention is that the outer circuit breakers are interconnected for simultaneous automatic operation and the trip levers of the intermediate circuit breakers are independently operable.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an end view of a multi-pole breaker comcircuit breakers which are spaced from each other in an assembly of breakers assembled in a side-by-side rela- FIG. 4 is an end view of the trip levers taken on the line lV-IV of FIG. 3; and

FIG. 5 is an elevational view of another embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Each circuit breaker 10-16 comprises a molded insu- ,lating housing part 18 and a molded insulating cover part 20. The housing part 18 is an open-sided member having a cavity into which the circuit breaker mechanism 22 is positioned during the assembly of the breaker. Thereafter the cover 20 is placedin position and four rivets are passed through aligned openings 24 (FIG. 2) in the housing parts 18 and 20 to secure the parts together. The circuit breaker housing comprises a front wall 26, a back wall 28, opposite end walls 30,

' and side walls 32.

As shown in FIG. 2 the circuit breaker mechanism 22 comprises a stationary contact 34, a movable contact 36, an operating mechanism 38, and a trip device 40. Inasmuch as the cicuit breaker'mechanism 22 is substantially similar to that disclosed in US. Pat. No. 3,475,710, only a general description of the operating parts will be included herein together with the additional parts which constitute the device of this invention.

The stationary contact 34 is mounted on a terminal conductor 42 which extrnds through a suitable opening attracting the armature 50 and releasing the lower right hand portion of the latch member 46. The lease spring 52 is pivotally mounted at the upper end of the armature 50. The operating mechanism 22 also comprises a cam 56 and a trip lever 58. The trip lever 58 comprises a hub 60 at the upper. end of the lever by which the I lever is rotatably mounted in opposed openings or apertures in opposite side walls 32 of each breaker 10-16.

The outer circuit breakers 10 and 16 include similar trip levers 58 and the intermediate circuit breakers 12 and 14 include trip levers 62 and 64 each of which is prising four circuit breakers mounted in side-by-side provided with similar hubs 66 and 68. As shown more particularly in FIG. 3 the hubs 66 and 68 comprise similar aligned bores 70 which extend completely through the adjacent hubs and provide a round passageway between the hubs 60 of the outer trip levers 58. Each hub 60 includes an aperture 72 (FIG. 4) of noncircular 58 is rotated, the motion is transferred through the tie bar 74 to the outer lever of the opposite end of the assembly. It is noted that when the tie bar 74 is rotated, the trip lever 62 and 64 remains stationary because the bores 70 merely act as conduits for the tie bar.

As shown in FIG. 3, the trip levers 62 and 64 operate automatically together due to interlock means including a projection 76 extending into a notch 78 which projection and notch are part of the adjoining hubs 68 and 66, respectively.

Rotation of either lever 58 is caused by release of the latch member 46 in either outer circuit breaker l and 16. When the armature 60 releases the latch member 46, said member rotates clockwise about its pivot point 59, causing the cam 56 to move against that trip lever 48, thereby causing rotation of the tie bar 74 to trip open the tie bars of both circuit breakers l0 and 16.

Likewise, the trip levers 62 and 64 are actuated simultaneously and automatically due to the interlock means including the interfitting projection 76 and notch 78. The trip levers 62 and 64 function independently of the outer levers 58 because the diameter of the bores 66 and 68 are greater than any crosssectional dimension of the tie bar 74 extending therethrough.

Anotherembodiment of the invention is shown in FIG. in which similar numerals refer to similar parts except where they differ from the embodiment shown in FIG. 3. The embodiment of FIG. 5 includes a tie bar 80 which extends through similar apertures 82 at the upper ends of the trip lever 58 which apertures have cross-sectional dimensions corresponding to that of the tie bar and fit snuggly thereon to enable rotation of one trip lever 58 in response to rotation of the other. In other words, the outer triplevers 58 are not provided with hubs 60 as are the trip levers 58 in the embodiment of FIG. 1.

Accordingly, the device of this invention provides new and novel means for automatically tripping the circuit breaker for two outer poles of the circuit without interrupting circuits through the intermediate circuit breakers which in turn are interconnected for automatic tripping of the poles handled by the intermediate circuit breakers.

We claim:

1. A circuit breaker assembly comprising at least four circuit breakers in side-by-side relationship and including two outer circuit breakers and at least two intermediate circuit breakers between the outer circuit breakers, each circuit breaker including a housing having opposite walls including aligned apertures, the apertures of each housing being registered with corresponding apertures of adjacent housings, each circuit breaker having relatively movable contacts and operating mechanism therefor, each circuit breaker comprising a latch member releasably restraining the operating mechanism and responsive to overload current conditions to release the operating mechanism to trip the breaker, a trip level in each circuit breaker and operatively associated with the operating mechanism, a rotatable tie bar extending through the apertures of the housing of the intermediate circuit breakers and interconnecting the trip levers of the outer circuit breakers, the trip levers of the outer circuit breakers being movable to a trip position upon movement of the latch member of either outer circuit breaker, the trip levers of the intermediate circuit breakers being interlocked and comprising hollow rotatable shafts through which the tie bar extends in a freely rotatable manner, and the trip levers of the intermediate circuit breakers being movable independently of the trip levers of the outer circuit breakers in response to movement of the latch member of either intermediate circuit breaker. 

1. A circuit breaker assembly comprising at least four circuit breakers in side-by-side relationship and including two outer circuit breakers and at least two intermediate circuit breakers between the outer circuit breakers, each circuit breaker including a housing having opposite walls including aligned apertures, the apertures of each housing being registered with corresponding apertures of adjacent housings, each circuit breaker having relatively movable contacts and operating mechanism therefor, each circuit breaker comprising a latch member releasably restraining the operating mechanism and responsive to overload current conditions to release the operating mechanism to trip the breaker, a trip level in each circuit breaker and operatively associated with the operating mechanism, a rotatable tie bar extending through the apertures of the housing of the intermediate circuit breakers and interconnecting the trip levers of the outer circuit breakers, the trip levers of the outer circuit breakers being movable to a trip position upon movement of the latch member of either outer circuit breaker, the trip levers of the intermediate circuit breakers being interlocked and comprising hollow rotatable shafts through which the tie bar extends in a freely rotatable manner, and the trip levers of the intermediate circuit breakers being movable independently of the trip levers of the outer circuit breakers in response to movement of the latch member of either intermediate circuit breaker. 